This invention relates to a programmable sequential logic circuit composed of an assembly of logic circuits associated with a memory. It may be used in any industry for the control of electronic or electromagnetic apparatus, and is particularly applicable to telecommunications.
The purpose of the invention is the provision of computer interfacing logic, particularly for computer controlled automatic switching centers (exchanges). In the current state of the art, computer control of exchanges may be devised in several forms: either a large computer (central processor) executes all tasks through various programmed or wired logic peripherals of low logic capability but high data handling capability, or else a set of minicomputers carry out assigned portions of the tasks and are under the overall control of a central computer.
Decentralization of functions is finding increasing acceptance, owing to the flexibility it procures and its freeing of the central computer from routine work.
However, the use of peripherals endowed with logic has certain disadvantages: (a) the creation of equipment precisely suited to desired functions leads to excessive diversity, whereas the use of production-run minicomputers is expensive, in that not all the capabilities of these devices are put to use, and (b) especially if it is desired to remove as many logic functions as possible from the switching network itself, the number of minicomputers required becomes rather large.